The Aspergillus nidulans spermidine synthase gene, spdA, is required for fungal differentiation.

Doralinda Guzman-de-Pena, Yuan Jin and Nancy Keller.


The Aspergillus nidulans spdA gene, encoding for a putative spermidine synthase, was cloned, sequenced, and localized on chromosome VIII. The deduced amino acid sequence has a high similarity with Saccharomyces cerevisiae spermidine synthase encoded by the spE3 gene. In both yeast and the filamentous fungus Neurospora crassa, spermidine and other polyamines are required for fungal differentiation processes. To investigate the function of SpdA on Aspergillus development, we constructed a spdA null mutant by replacing a portion of the coding region with the argB gene. The DspdA strain, which accumulates the biosynthetic precursor of spermidine, putrescine, has an absolute requirement of spermidine for growth, sporulation and sterigmatocystin production. Wildtype growth and development could not be recovered in the DspdA strain by a high concentration (3mM) of either putrescine or spermine but was partially recovered by a high concentration (3mM) of spermidine.

abstract No: 

Fungal Genet. Newsl. 46 (Supl):

Full conference title: 

Fungal Genetics Conference 20th
    • Fungal Genetics Conference 20th (1999)